1. Field of the Invention
The present invention relates generally to the field of switchgear and more particularly to a switch operator which may be installed either during manufacture or during retrofit to installed switchgear to provide power operation of manually operable switchgear, the switch operator including an arrangement for selective decoupling of the switch operator from the switch-gear that is operable without the need for tools and also providing for manual operation without the need to decouple or disconnect or remove any parts.
2. Description of the Related Art
Various switch operators and decoupling arrangements are known for switchgear and for high-voltage switches. For example, U.S. Pat. No. 4,804,809 is directed to a motor operator for switchgear. A sleeve (not shown) interconnects a connection shaft 80 to the operating shaft 40 of the switchgear operating mechanism. To effect manual operation, bolt 102 (FIGS. 6 and 7 of the '809 patent) is removed from the connecting shaft 80 to allow the drive element 94 to thereafter be separated from the end portion of the connecting shaft 80 along with the pin-like head 90 of the stud 88. Nex shown in FIG. 6, a wrench 126 is placed over the shaft 80 to perform the manual operation. The manual operation cannot be performed until the drive element 94 is removed to uncouple the clevis assembly 76 from the shaft 80. The removable drive element also permits the motor operator 46 to be tested independent of and without operation of the switchgear opening and closing mechanism. To summarize, manual operation requires decoupling. Additionally, the decoupling and manual operation each require the disassembly of parts.
Other decoupling arrangements for various apparatus are shown in the following U.S. Patents and publications: U.S. Pat. Nos. 1,146.446; 3,508,179; 4,107,486; 4,190,755; 4,351,994 and 4,466,520; S&C Electric Company Photo Sheet 740-4.1, Sept. 23, 1986., H. K. Porter Catalog No. 1-160, April 1971; I.T.E Imperial Corporation, Catalog Section 13.4.1.1-13.4.1.2, MO.10 Motor Operator, Aug. 30 1986; and Siemens-Allis Brochure DS 4.2. Type CM.4A Motor Operating Mechanism, June 1983.
While the aforementioned arrangements may be generally useful for their intended applications none of these arrangements is both generally suitable for retrofit in the field while also providing desirable drive configurations, decoupling arrangements and direct manual operation features which do not require the decoupling or disconnection of any parts.